// *******************************************************************
// ArrayOperations16.java By: Aiman Hanna (C) 1993 - 2016
//
// This program illustrates more on two-dimensional arrays.
// The program shows how, for example, they can be passed as
// parameters to functions. You should notice that this is
// done in the fashion for passing one-dimension array.
// See ArrayOperations9.java for comparisons.
//
//Key Points: 1) Passing Two-Dimensional Arrays as Method Parameters
// *******************************************************************
import java.util.Scanner;
import java.util.Random;// Needed to generate random values
class ArrayModifier
{
publicstaticint intArrModifier(int[][] ar, int ov, int nv)
{
// This method will expect a two-dimensional array of integers,
// as well as two integer values.
// The method will search the array for every occurrence
// of the first passed value; the is ov, and if found replace
// it with a new value, that is nv.
// Notice that when an array is passed as a parameter, the
// lengths of the array are NOT to be specified.
int ctr = 0, i, j;
for (i = 0; i < ar.length; i++)
{
for (j = 0; j < ar[i].length; j++)
{
if (ar[i][j] == ov)
{
// if the value is found, change it and increase the counter
// to trace how many changes were performed at the end
ar[i][j] = nv;
System.out.println("A replacement has been made at index [" + i + "][" + j +"]");
ctr++;
}
}
}
return ctr;
}
}
publicclass ArrayOperations16
{
publicstaticvoid main (String[] args)
{
int i, j, rSize, cSize, counter =0, val1, val2;
Scanner kb = new Scanner(System.in);
// Create a Random object
Random rand = new Random();
// Allow the user to enter the dimensions of the array to be created
System.out.print("Please enter the row and column sizes of the array, respectively:");
rSize = kb.nextInt();
cSize = kb.nextInt();
// Create a two-dimensional array of integers
int[][] arr = newint[rSize][cSize];
// Initialize the array with random values between 0 and 99
// Now you must use "length" for both rows and columns
for (i = 0; i < arr.length; i++)// This will give the row length;
{// in other words how many rows
for (j = 0; j < arr[i].length; j++)// Notice the difference;
{// that is length of each column;
arr[i][j] = rand.nextInt(100);// 100 will force the generator
// to get a value between 0 & 99
}
}
// Show the contents of the array
System.out.println("Here are the contents of the array");
System.out.println("======");
for (i = 0; i < arr.length; i++)
{
for (j = 0; j < arr[i].length; j++)
{
System.out.printf("%4d", arr[i][j]);
}
System.out.println();
}
// Now ask the user to enter the value that he/she wishes to replace
System.out.println();
System.out.print("\nPlease enter two integers to search and replace respectively: ");
val1 = kb.nextInt();
val2 = kb.nextInt();
System.out.print("\nAttempting modifications on array arr \n");
counter = ArrayModifier.intArrModifier(arr, val1, val2);
if (counter > 0)
{
System.out.println(counter + " changes were made on arr1");
System.out.println("\nHere are the contents of arr1 after modifications: ");
System.out.println("======");
for (i = 0; i < arr.length; i++)
{
for (j = 0; j < arr[i].length; j++)
{
System.out.printf("%4d", arr[i][j]);
}
System.out.println();
}
}
else
System.out.println("Value " + val1 + " was not found in the array; no changes were made.");
kb.close();
}
}
/* The output
Please enter the row and column sizes of the array, respectively:6 10
Here are the contents of the array
======
53 94 61 70 81 91 32 84 52 20
34 66 50 32 15 42 4 27 87 4
98 15 40 23 48 42 31 27 6 54
32 91 15 74 35 49 75 3 11 5
10 44 58 51 93 14 84 34 11 3
77 37 29 73 94 0 3 72 60 65
Please enter two integers to search and replace respectively: 91 88
Attempting modifications on array arr
A replacement has been made at index [0][5]
A replacement has been made at index [3][1]
2 changes were made on arr1
Here are the contents of arr1 after modifications:
======
53 94 61 70 81 88 32 84 52 20
34 66 50 32 15 42 4 27 87 4
98 15 40 23 48 42 31 27 6 54
32 88 15 74 35 49 75 3 11 5
10 44 58 51 93 14 84 34 11 3
77 37 29 73 94 0 3 72 60 65
*/
/* Run Again
Please enter the row and column sizes of the array, respectively:6 12
Here are the contents of the array
======
56 67 80 39 6 75 4 98 35 36 68 79
22 67 12 57 54 67 25 97 11 78 81 85
88 52 9 81 81 64 65 58 88 27 41 32
24 62 36 52 62 64 59 47 74 15 73 6
26 25 30 79 26 59 7 13 98 45 3 57
25 35 12 73 64 97 50 61 44 54 97 44
Please enter two integers to search and replace respectively: 77 14
Attempting modifications on array arr
Value 77 was not found in the array; no changes were made.
*/